Allow using RGB_565 on API < 26

And increase PageLoader cache size on API 26+

app/src/main/kotlin/com/hippo/ehviewer/EhApplication.kt

@@ -33,6 +33,7 @@ import coil3.network.NetworkFetcher
 import coil3.network.ktor3.asNetworkClient
 import coil3.request.ErrorResult
 import coil3.request.ImageRequest
+import coil3.request.allowRgb565
 import coil3.request.crossfade
 import coil3.serviceLoaderEnabled
 import coil3.util.DebugLogger
@@ -173,6 +174,8 @@ class EhApplication :
             add(DownloadThumbInterceptor)
             if (isAtLeastO) {
                 add(HardwareBitmapInterceptor)
+            } else {
+                allowRgb565(true)
             }
             add(CropBorderInterceptor)
             add(DetectBorderInterceptor)

app/src/main/kotlin/com/hippo/ehviewer/gallery/PageLoader.kt

@@ -30,7 +30,7 @@ import okio.Path
 
 private val progressScope = CoroutineScope(Dispatchers.IO)
 private const val MAX_CACHE_SIZE = 512 * 1024 * 1024
-private const val MIN_CACHE_SIZE = 128 * 1024 * 1024
+private const val MIN_CACHE_SIZE = 256 * 1024 * 1024
 
 context(CoroutineScope)
 abstract class PageLoader(val gid: Long, var startPage: Int, val size: Int, val hasAds: Boolean = false) : AutoCloseable {
@@ -39,7 +39,7 @@ abstract class PageLoader(val gid: Long, var startPage: Int, val size: Int, val
 
     private val cache = SieveCache<Int, Image>(
         maxSize = if (isAtLeastO) {
-            (OSUtils.totalMemory / 16).toInt().coerceIn(MIN_CACHE_SIZE, MAX_CACHE_SIZE)
+            (OSUtils.totalMemory / 8).toInt().coerceIn(MIN_CACHE_SIZE, MAX_CACHE_SIZE)
         } else {
             (OSUtils.appMaxMemory / 3 * 2).toInt()
         },